madman
Super Moderator
There is a strong association between benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and sexual dysfunction. While transurethral resection of the prostate (TURP) is considered the standard BPH treatment, it is however associated with a high rate of erectile and ejaculatory dysfunctions. Over the past decade, new and novel minimally invasive BPH therapies have been shown to improve various parameters of voiding domains while minimizing adverse sexual effects. These minimally invasive BPH therapies can be largely be divided into those with cavitating technology (Rezum, Histotripsy, Aquablation), intra-prostatic injections (Botulinum neurotoxin Type A, Fexapotide Triflutate, prostate-specific antigen-activated protoxin PRX-302), and mechanical devices which include intraprostatic stents (Urospinal 2TM, MemothermTM, MemokathTM, and Allium triangular prostatic stentTM) and intraprostatic devices (iTINDTM, UroliftTM), as well as prostatic artery embolization. Published literature on these technologies showed reasonable preservation of erectile function with limited data reported on the ejaculatory domain. Further validation of the performance of these novels minimally invasive treatment options for LUTS due to BPH in well-designed and multi-center studies are desired, to evaluate their role (or lack of such a role) in clinical practice and whether these BPH therapies can provide equivalent standard or better than TURP.
INTRODUCTION
Benign prostatic hyperplasia (BPH) contributes to lower urinary tract symptoms (LUTS) such as urinary hesitancy, dribbling, weak stream, and frequency [1].Epidemiological studies showed that 50% of men in their fifties will have BPH symptoms [2], and the incidence of LUTS in this age group is estimated as high as 25% in some studies[2,3]. Erectile dysfunction (ED) and ejaculatory disorders are prevalent in sexually active men with LUTS and both conditions correlate with LUTS severity independently of age and cardiovascular comorbidities [3,4]. The prevalence of ED and concurrent BPH has been reported to be as high as 40% and men with ED are 6 times more likely to have BPH than men without BPH [5]. Moreover, it is known that the severity of LUTS and sexual dysfunction are both independently correlated with lower quality of life (QoL) scores [6].
The link between LUTS and ED has been explained through several pathophysiological pathways involving nitric oxide guanosine monophosphate and RhoA/Rho-kinase, metabolic syndrome, autonomic hyperactivity, pelvic ischemia, sex hormones imbalance, inflammatory pathway, and psychological factors [7]. Clinically, the resolution of LUTS appears to correlate with an improvement in sexual function but not in a linear fashion [8]. There appears to be an intricate balance between adequate prostatic tissue resection to improve the bladder outflow tract and preservation of critical structures responsible for sexual function.
Although transurethral resection of the prostate (TURP) is considered the surgical standard for BPH therapy, it is however, associated with a high rate of male sexual dysfunction such as ED (3.4%–32%) and ejaculatory dysfunction (53%–72%) [9].The proposed pathophysiologic mechanisms for retrograde ejaculation and/or decreased ejaculation are related to inadvertent resection of tissue paracollicular and supracollicular tissue at the verumontanum and decreased the volume of prostate tissue following resection respectively [1,8]. Furthermore, the use of high-frequency generated energy current close to the prostate capsule may cause neuropraxia injury to the nearby neuromuscular bundles, resulting in the development and/or progression of ED [1,9]. Additionally, some studies highlighted the potential psychosocial factors or ensuing urinary symptoms such as urgency or incontinence as contributing factors to the subsequent development of male sexual dysfunction [2-4, 6].
Hence, over the last decade, there is a paradigm shift towards effective yet minimally invasive BPH surgical therapy with minimal sexual dysfunction postoperatively. The following article reviews the current minimally invasive BPH surgical treatments with an emphasis on the impact of these therapies on sexual function preservation (Table 1).
1.Cavitation technology or techniques
Similar to conventional TURP which resects prostate tissue to open the prostatic urethra and bladder outlet, these novels minimally invasive BPH devices cause prostatic tissue cavitation through various energy sources.
1) RezumTM - convective water vapor energy therapy
2) Histotripsy
3) Aquablation system
2.Intra-prostatic injectables
Intra-prostatic injections with different agents have been explored with the proposed advantages of being administered under local anesthesia in an outpatient setting and are suitable for older and co-morbid patients who are not suitable or fit for surgery. These injectable drugs include Botulinum neurotoxin type A, Fexapotide Triflutate (FT) (NX-1207; Nymox Pharmaceutical Corporation, Hasbrouck Heights, NJ, USA), and PRX-302 (Topsalysin; Sophiris Bio Corp, La Jolla, CA, USA). Of note, the ethanol injection has been abandoned due to significant TRAE.
1) Botulinum neurotoxin Type A
2) Fexapotide Triflutate (NX-1207)
3) Prostate-specific antigen-activated protoxin (PRX-302)
3.Mechanical devices
1) Intraprostatic stents The first experiment on the use of expandable metallic stents as a valid treatment for BPH was published by Fabian in 1980 [42]. Since then, there have been multiple intraprostatic stents, either temporary non-epithelializing type or a permanent type that fasten onto the prostate stroma through epithelialization, have been introduced and tested to keep the prostatic urethra patent. Given the dearth of robust evidence, some of these stents have been phased out and withdrawn from the commercial market.
(1) Urospinal 2TM
(2) MemothermTM
(3) MemokathTM
(4) AlliumTM triangular prostatic stent
2) Intraprostatic devices
(1) iTINDTM (i-Temporary Implantable Nitinol Device)
(2) Prostatic urethral lift (UroliftTM)
4.Prostatic artery embolization
CONCLUSIONS
It has become evident that an improvement in LUTS coupled with the preservation of male sexual function especially erectile and ejaculatory functions are of paramount importance for many sexually active men who are contemplating BPH surgery. To date, there are very few direct comparative clinical trials among these minimally invasive BPH technologies, and further studies are required to ensure optimal patient selection, analyze cost-effectiveness, and counsel patients on longer-term clinical outcomes and safety profile.
INTRODUCTION
Benign prostatic hyperplasia (BPH) contributes to lower urinary tract symptoms (LUTS) such as urinary hesitancy, dribbling, weak stream, and frequency [1].Epidemiological studies showed that 50% of men in their fifties will have BPH symptoms [2], and the incidence of LUTS in this age group is estimated as high as 25% in some studies[2,3]. Erectile dysfunction (ED) and ejaculatory disorders are prevalent in sexually active men with LUTS and both conditions correlate with LUTS severity independently of age and cardiovascular comorbidities [3,4]. The prevalence of ED and concurrent BPH has been reported to be as high as 40% and men with ED are 6 times more likely to have BPH than men without BPH [5]. Moreover, it is known that the severity of LUTS and sexual dysfunction are both independently correlated with lower quality of life (QoL) scores [6].
The link between LUTS and ED has been explained through several pathophysiological pathways involving nitric oxide guanosine monophosphate and RhoA/Rho-kinase, metabolic syndrome, autonomic hyperactivity, pelvic ischemia, sex hormones imbalance, inflammatory pathway, and psychological factors [7]. Clinically, the resolution of LUTS appears to correlate with an improvement in sexual function but not in a linear fashion [8]. There appears to be an intricate balance between adequate prostatic tissue resection to improve the bladder outflow tract and preservation of critical structures responsible for sexual function.
Although transurethral resection of the prostate (TURP) is considered the surgical standard for BPH therapy, it is however, associated with a high rate of male sexual dysfunction such as ED (3.4%–32%) and ejaculatory dysfunction (53%–72%) [9].The proposed pathophysiologic mechanisms for retrograde ejaculation and/or decreased ejaculation are related to inadvertent resection of tissue paracollicular and supracollicular tissue at the verumontanum and decreased the volume of prostate tissue following resection respectively [1,8]. Furthermore, the use of high-frequency generated energy current close to the prostate capsule may cause neuropraxia injury to the nearby neuromuscular bundles, resulting in the development and/or progression of ED [1,9]. Additionally, some studies highlighted the potential psychosocial factors or ensuing urinary symptoms such as urgency or incontinence as contributing factors to the subsequent development of male sexual dysfunction [2-4, 6].
Hence, over the last decade, there is a paradigm shift towards effective yet minimally invasive BPH surgical therapy with minimal sexual dysfunction postoperatively. The following article reviews the current minimally invasive BPH surgical treatments with an emphasis on the impact of these therapies on sexual function preservation (Table 1).
1.Cavitation technology or techniques
Similar to conventional TURP which resects prostate tissue to open the prostatic urethra and bladder outlet, these novels minimally invasive BPH devices cause prostatic tissue cavitation through various energy sources.
1) RezumTM - convective water vapor energy therapy
2) Histotripsy
3) Aquablation system
2.Intra-prostatic injectables
Intra-prostatic injections with different agents have been explored with the proposed advantages of being administered under local anesthesia in an outpatient setting and are suitable for older and co-morbid patients who are not suitable or fit for surgery. These injectable drugs include Botulinum neurotoxin type A, Fexapotide Triflutate (FT) (NX-1207; Nymox Pharmaceutical Corporation, Hasbrouck Heights, NJ, USA), and PRX-302 (Topsalysin; Sophiris Bio Corp, La Jolla, CA, USA). Of note, the ethanol injection has been abandoned due to significant TRAE.
1) Botulinum neurotoxin Type A
2) Fexapotide Triflutate (NX-1207)
3) Prostate-specific antigen-activated protoxin (PRX-302)
3.Mechanical devices
1) Intraprostatic stents The first experiment on the use of expandable metallic stents as a valid treatment for BPH was published by Fabian in 1980 [42]. Since then, there have been multiple intraprostatic stents, either temporary non-epithelializing type or a permanent type that fasten onto the prostate stroma through epithelialization, have been introduced and tested to keep the prostatic urethra patent. Given the dearth of robust evidence, some of these stents have been phased out and withdrawn from the commercial market.
(1) Urospinal 2TM
(2) MemothermTM
(3) MemokathTM
(4) AlliumTM triangular prostatic stent
2) Intraprostatic devices
(1) iTINDTM (i-Temporary Implantable Nitinol Device)
(2) Prostatic urethral lift (UroliftTM)
4.Prostatic artery embolization
CONCLUSIONS
It has become evident that an improvement in LUTS coupled with the preservation of male sexual function especially erectile and ejaculatory functions are of paramount importance for many sexually active men who are contemplating BPH surgery. To date, there are very few direct comparative clinical trials among these minimally invasive BPH technologies, and further studies are required to ensure optimal patient selection, analyze cost-effectiveness, and counsel patients on longer-term clinical outcomes and safety profile.
